


The mirror

by Lillywrites



Category: Undertale
Genre: Fell is a dirty sinner, M/M, just angst and fluff, refrences to porn, sfw
Language: English
Status: In-Progress
Published: 2016-12-16
Updated: 2017-03-20
Packaged: 2018-09-08 17:44:16
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 3,482
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8854939
Author URL: https://archiveofourown.org/users/Lillywrites/pseuds/Lillywrites
Summary: Underswap Papyrus goes into an old shop and decides to buy a nice looking mirror for his Sans. Underswap Sans finds out that the mirror can show different versions of yourself from across multiple AUs he stumbles across Underfell and becomes endorsed by that version of himself.





	1. A mirror

**Author's Note:**

> US! Papyrus-Stretch  
> US! Sans-Blue/Berry/Blueberry  
> UF! Sans-Fell

**Summary for the Chapter:**

> Stretch buys Blue a new mirror.

**Notes for the Chapter:**

> Fell - UF! Sans  
> Blue - US! Sans  
> Stretch - US! Papyrus  
> Edge - UF! Papyrus

Stretch casually walked to the store behind NTT's hotel smoking a cigarette. Earlier Blue had given him some gold and told him to get some food and drop off Alphys' axe he had used for training. So just like the lazy bones he was he looked for the nearest store near Alphys home in Hotland. While looking around in the small alleyway store he saw an old mirror. It was on sale, only 50g. Blue had given him way more money than he needed. "What if the food costs more than normal Papy!" He had exclaimed. Not wanting to argue he had taken the money and teleported to Alphy's house.

Soon Stretch had brought some food and the mirror and teleported home. Blue was busy making tacos in the kitchen so Stretch secretly teleported the mirror into Blue's room. He slumped onto the couch and turned on the tv. Blue finished making the tacos and gave one to Stretch. It tasted like Blue had burnt an old boot then sprinkled mashed up vegetables on top. Stretch, not wanting to upset his brother, gave it back.  
"Eh don't worry 'bout it bro got some stuff from Muffet's earlier."  
"Papy you knew I was cooking tonight! Why did you get Muffet's?" Blue didn't look impressed at all. Stretch shrugged it off.  
"Also Papy you took forever! I've already watched all the Nabstabot reruns and was able, with my amazing cooking skills, to create the culinary art that is my tacos! The magnificent Sans won't allow you to take so long in the future!" Blue exclaimed. Stretch glanced at the clock. He had taken hours.  
"Taco the time I think it's about time to get ready for bed bro." Stretch said calmly not wanting to give away the surprise in his brother's room. Blue groaned and headed to his room.

Stretch heard a squeel and he saw Blue sprinting down the stairs. Stretch teleported to the staircase just as Blue tripped. Stretch grabbed his leg so he wouldn't fall on his face. He put Blue down. He had stars in his eyes and was jumping from foot to foot.  
"Papy did you get me the mirror!?" He almost screamed. Stretch nodded and Blue's face lit up. Blue hugged Stretch as hard as he could. He then let go and raced up the stairs. Stretch reckoned he'd be up all night looking at the mirror. Blue tended to get over excited. Stretch laid down on the couch and fell asleep.


	2. An alternative universe

**Summary for the Chapter:**

> Blue learns to channel his magic through the mirror to see alternative versions of himself.

**Notes for the Chapter:**

> (Head cannon) Ink can feel people opening portals into his spot in the multiverse and people using magic to watch him.  
> Outertale created by 2mi127  
> Link-->http://2mi127.tumblr.com  
> Underswap created by popcornpr1nce  
> Link-->http://popcornpr1nce.tumblr.com/  
> Inktale created by comyet  
> Link-->http://comyet.tumblr.com/  
> Underfell created by ???(someone awesome who deleted their blog)  
> Undertale created by Toby Fox

Blue looked around the mirror it was beautifully carved with spirals and flowers. Blue ran his finger over the design. He smiled and started to admire himself in the mirror. He summoned a bone to look like he was ready for a battle and the mirror started to ripple. Blue ignored it and continued to make poses and admire himself. He didn't realise he was still holding the bone until it flew out of his hand and straight into the mirror. Blue gasped and ran over to the mirror to see the damage. 

The bone had not shattered the mirror or even scratched the glass. Blue was more than confused as he pick the bone off the ground. He tried to desummon the bone but it stayed in his hand. He checked it. 'Just a regular bone.' The put the bone in a box then turned his attention to the mirror. It was rippling and seemed to reflect static. Blue freaked out and summoned a bone and tried to break the mirror with it. It seemed that the mirror absorbed the magic from the bone. 

The mirror stopped rippling and was now showing another version of himself with a large paintbrush in hand. They shivered then looked around. Blue tried to break the mirror again with a new bone. It once again soaked up the magic and showed another version of himself. Only this version of himself was floating in the galaxy and was wearing a dark blue jumper with yellow stripes. Blue experimentally put a new bone to the mirror it changed once again. This time it was focusing on a alternative version of himself with a blue hoodie and pink slippers. He appeared to be sleeping at his sentry station. 

It was now midnight and Blue was still looking at different AU's. Sometime earlier Blue realised that straight up sending magic into the mirror worked best. Blue kept flicking through AU's like someone would switch channels on a tv. Then Blue found a particularly interesting AU. Everyone was either wearing black or red. Most walked timidly and other were fighting others. This version of him had sharp teeth and one gold tooth. He was angry and shouting out swear words. Blue visibly cringed at this but continued to watch.


	3. Underfell

**Summary for the Chapter:**

> Blue lets the world of Underfell consume him.

**Notes for the Chapter:**

> If we get 200 hits I'll post a drawing for this fan fic on my tumblr http://xxlilly17xx.tumblr.com

It had been two days since Stretch had gotten Blue the mirror and he hadn't seen him since. Which was strange considering that Blue always went to patrol no matter what. US Alphys was highly suspicious but Stretch as always shrugged it off. He didn't consider it a problem. He told US Alphys it was probably one of his new crazes. 

It was when a whole week went by without Blue leaving his room that Stretch got worried. He had to take food and water up to Blue. As far as he knew Blue hadn't seen any natural sunlight for days. There was always talking creeping through the cracks in Blues door. When he tried to ask about it Blue sound proofed the room with his magic. US Undyne had come and tried to come in to Blue's room but the door was locked. They had slipped a note under the door asking to be let in but he still wouldn't unlock the door. In fact the door didn't unlock at all not even to get food and water. So Stretch decided to start teleporting it in. 

Behind the door Blue was still watching underfell. He had watched their human come through and create happiness in a dark world. Many had tried to kill the human but to no avail. And now everyone in their Snowdin was happy. That version of him with he had started to call Fell was even happier than most. Blue decided he would find a way to bring him to his AU or he would go into theirs.

Meanwhile outside US Undyne, US Alphys and Stretch sat thinking about what to do. Undyne had noticed Stretch teleporting food into Blues room.  
"H-hey Pap. W-why don't y-you t-teleport yourself into Sans' room?" She asked. Stretch just shrugged and mumbled something about privacy. US Alphys had gotten sick of this and slammed her fists down on the table making Undyne peep and back away from the table.   
"WHAT ARE WE DOING LETS BUST INTO HIS ROOM AND GET HIM OUT HERE!" Alphys screamed. Stretch shook his head. He didn't want to invade his brother's personal space. Last time Stretch went into his bros room without asking Blue had burst into tears. It had taken him a month to clam down completely. And Stretch wasn't about to make that mistake.

Two weeks had passed and Stretch was starting to consider breaking into the room. Little did he know his bro had a plan.


	4. New world, Same people

**Summary for the Chapter:**

> Blue find some out how to travel to other universes and Stretch finds something interesting.

Fell had never been happy. He'd always been depressed or mad. But when the human came through the whole of Snowdin seemed to change. That was everyone expect Fell and his brother. Grillby's bar had changed, it was no longer full of drunks and fights weren't breaking out every minute. Everyone was content to some extent and Fell hated it. It wasn't any better for Edge either. He was just trying to the capture the human but everyone in the town had disabled his traps and resigned from the Royal Guard. Edge of course was enraged. The human was always just out of his reach. When he befriended the human and watched them leave for Waterfall Fells facade slowly fell away. He made more puns, he drank less and actually wished the human luck.

Blue had been rationing his food since he came up with the plan and thing that wouldn't go off for a while would be stored in a plastic bag and put beside the mirror. He had started to experiment with the mirror a while ago and had figured out how to seemingly breach the barrier between his universe and theirs. All he had to do was focus all his magic into the mirror. And that meant all his magic. There was a risk of it failing and death due to low magic but Blue had to hope. He grabbed his food and walked through the portal.

Stretch was extremely worried now and had decided to teleport a note into Blue's room with a warning and gave him two hours to respond. With no response Stretch teleported into Blue's room. It seemed normal. The mirror he had brought was in the corner of the room and Blue's spaceship bed was still in its normal spot. Only it looked like it hadn't been used for days. There was a thin layer of dust on the frame of the bed. Dust was never seen in Blue's room and Stretch started to worry. He saw a pile of dirty dishes on the table where Blue's figurines usually stood. Insted there where drawings and multiple plans. The draws dipicted Blue with sharp teeth and one gold tooth and dressed in black and red. On the plans there where desperate writing and drawings of the mirror. Stretch took the plans and drawings and teleported to Undyne's lab.

Fell was walking back to his house after spending his day at Grillby's when he saw a small skeleton dressed in blue and whites passed out in the snow. He turned the skeleton over. It had his face. Which of course freaked him out but he picked him up and took him to his home. The couch was stained with mustard so he took the stranger to his brothers room where he put him in his brothers bed. He was sure Edge wouldn't mind and gave the stranger a hot water bottle and left him in there with a plate of spaghetti on the table for the new skeleton. Fell sat on the couch downstairs watching tv. He had decided he would take tomorrow off to get the stranger checked out and to look after them. But he didn't know what the stranger would do when he woke up.


	5. Chapter 5

**Summary for the Chapter:**

> Stretch freaks out even more after his little bro goes missing. Fell has to deal with a new routine.

**Notes for the Chapter:**

> The picture I promised once we hit 200 hits  
> http://xxlilly17xx.tumblr.com/post/155653119182/this-is-around-chapter-2-and-3-its-just-a-little

It was a couple of days later when Stretch heard from Undyne. She had concluded that the plans where to run away and the paragraphs of reports were talking about the mirror Stretch had brought Blue but other than that it was surrounded in mystery. Of course the window and door were both locked so how could have he gotten out? In Underfell it had been two or three days. Edge had cleaned the couch to an okay extent when he saw the stranger in his bed. The stranger didn't wake up once. Edge had allowed Fell to take up to a week off as now he was apparently generous. That's when the stranger started to wake up. Fell rushed over from the kitchen at the sound of a groan. The slightly smaller skeleton was looking around confused but when he saw Fell his face seemed to light up. "It's you!" Blue yelled and leapt towards Fell. Fell took a step back just before Blue was able to touch him. "Woah woah. First off who the f*** are you secondly do I know you?" Fell asked. "Language!" Blue scolded, "My name is Sans and you don't know me but I know you." Fell had a look of shock and anger on his face. "Look you f***ing punk that's my name and ain't no stranger I found in the snow is stealing it! And what do you mean you know me but I don't know you?" He yelled and pinned Blue up to the wall. Edge walked in and took in the scene before him. There was a very angry Fell muttering curses under his breath and the stranger his brother found and brought home one night was pinned against the wall was blushing and sweating like crazy. "HOLY SH*T SANS IS THIS YOUR BOYFRIEND! I DIDNT KNOW YOU WERE F***ING GAY!" Edge screamed. Fell whipped his head around and let the Blue go. "AW F*** NO! He stole my f***ing name and I'm getting payback." Fell growled. Edge pushed Fell aside and picked up the smaller skeleton and dropped him on the couch. "First off stranger is your name really Sans?" Edge asked and the stranger nodded, "Hm that won't work how about a nick name?" The stranger nodded again. "How about Blue? Because of your scarf," Edge asked. Blue nodded contently and Edge's chest swelled up with pride, "So you are now Blue." Blue smiled and Fell scrowled and teleported up to his room. Stretch was at his house and it was a mess. Socks were littered on the floor with honey bottles and cigarette butts. Most monsters felt sorry for him and others scoffed. They'd insult him and say Blue ran away because of him. So he'd decided to stay put in the house. The only monsters he allowed in were Alphys and Undyne. They regularly checked up on him and got him food. Stretch had gone beyond lazy at this point he was a depressed slob. Alphys and Undyne knew it had only been a few days without Blue being seen and knew Stretch shouldn't be like this in a couple of days, but they also knew he lived for Blue.

Blue became part of Fell's daily routine. Get the annoying dog away, pick up his sock then put it somewhere else in the house, check on Blue, have a nap. He was sick and tired of Blue. Blue was clingy and spoiled. But the house was clean so he wouldn't complain. As long as Edge was keeping Blue under this roof Fell has to deal with it.


	6. What the hell!?

It had been a week now and Blue was still sleeping on the sofa. Edge was going to get the shed renovated so in the meanwhile they had to find Blue somewhere else to sleep.  
Edge walked into the living room as Blue was clinging onto Fell's arm while he was trying to watch Metaton.  
"Brother, Blue, its has come to my attention that one of us is still sleeping on the sofa so until I get our garage renovated Blue will sleep in one of our rooms. So Blue which room would you like to sleep in?"  
Without any hesitation he replied with Fell.  
"HELL NO!" Fell screamed but it went unheard by Blue and Edge who were discussing getting another bed from the dump. So now he was stuck 24/7 with a random creep that just happened to have the same name as him.  
He was done. He stomped to the door opening it then slamming it shut. He walked through the cold that nipped at this bones. He walked through the deep woods where no monster ever went in fear they'd lose them selves forever. He found his 'rage' area after a couple of hours when he realised he could've of just teleported and that made him boil with more rage than ever. The trees had scratches and huge chunks taken out of them. The snow was gone and it wasn't nearly as cold as the rest of the forest. He summoned a gaster blaster.

~~Blue's POV~~  
Fell slammed the door shut. I flinched and looked up at Edge. He was going on about cleaning Fell's messy room to make space for my bed.  
"Edge," He looked down at me suddenly very aware of my presence.  
"Yes Blue?,"  
"Where did Fell go?" He sighed.  
"Into the forest I'd believe, he has always goes there when he doesn't feel like grillbys or staying here. He should be back in a couple of hours." I looked at the door which was falling off its hinges. I felt so bad, it was because of me that he left. The one skeleton I'd ever really loved had gone because of me. That's when I had a great idea.  
"Let's clean the house up for when he comes back!" I shouted happily. Edge seemed to like the idea and nodded in approval.  
"You may clean the house but no going through my room or throwing out the spaghetti in the fridge, I'm still waiting for Fell to eat it," Blue nodded happily, "I need to go on patrol and get you a bed from the dump. Feel free to make anything for yourself while I'm gone. Cleaning supplies are in the kitchen." Blue was bouncing on the spot happily.  
"Take care!" Blue shouted as Edge left. He ran to the kitchen and got out the cleaning supplies. He started in the kitchen, scrubbing the greasy floors and cleaning the gross fridge leaving the spaghetti with little notes for Fell on them in the fridge and throwing out the old spoiled spaghetti. He even got the year old mustard stains out of the couch which was not an easy feat. That's when he got to Fell's room. It was pretty much their shared room now so he walked in.  
IT WAS DOOMSDAY IN THERE. Blue gawked at the mess of a bed and the socks littered on the floor. He first cleaned and vacuumed the floor then the bed. Then he noticed Fell's computer. Curiosity got the better of him as he turned it on and went through his history. The multiple universe theory, multiple versions of you and a weird link that had the words 'Good Time'. He clicked on it and saw the most sin ever. He started for a moment then screamed and shutdown the computer. He ran down to the couch and just stared.  
~~Third person POV~~  
That's were Edge found him two hours later.  
"Blue?" He went up to Blue and lightly poked him. Blue screamed and sobbed.  
"Blue, uh, what's wrong?" He asked sitting down next to Blue.  
"THE HORROR! I COULD DEAL WITH THE ROOM BUT--" Blue broke down. Edge realised he must've gone through Fell's history.  
"Sorry Blue I should've warned you about that." Blue got a tiny bit better after that but was still pretty shaken up. They made some spaghetti tacos for themselves and Fell.  
Fell stumbled through the door at 6pm. Blue went up to him and hugged him muttering apologies. Fell patted his skull gently. Blue blushed and looked at Fell. Droopy eyes, not walking straight, mumbling. He was drunk. Blue was mad now. He looked at him with the most sour face he could manage.  
Fell laughed, "You look cute when you pout, I didn't even notice before." Blue blushed and made Fell lean on him for support as he lead him to his room.  
'Don't think about it Sans he is just drunk it's just drunk talk. Papyrus has gotten drunk before but not to this extent. Maybe it's not drunk talk. NO just take him to his room.' Blue thought as he walked up the stairs. He laid Fell down on his newly clean bed. He didn't realise Fell had him held tightly to his chest until Fell tightened his grip. Blue fell down next to Fell on the bed and realised he was stuck so he snuggled close to Fell and drifted off to sleep.

Back in underswap Stretch was horrible, he hadn't left the couch in a week, he didn't go to work or clean or even pay bills.   
Toriel was coming to have a word with Stretch. She pushed open the door and saw Stretch half dead sitting on the couch hugging one of Blue's scarves. It broke her to see one of her subjects like this.  
She cleared her throat and made Stretch look at her.   
"It has come to my attention that you have not paid for water and electricity nor have you attended your sentry duties in over a week. And I have come to tell you personally that unfortunately due to absence you have been fired from your job as a sentry." Stretch looked at her with his dark depressed eyes. She felt a pang of guilt and pity.   
"I will allow you to keep your house but I'm afraid doing nothing won't get Sans back Papyrus. Everyone misses him. Whether they want to believe it or not. If it makes you feel better Alphys made you a stay at home Snowdin lookout guard. She made that job just for you. Please don't mess it up if not for me then for Sans." She smiled and walked out. He looked up.


End file.
